Implemented cancel connect.

remoting/webapp/me2mom/remoting.js

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /** @suppress {duplicate} */
 var remoting = remoting || {};
 
 (function() {
 'use strict';
 
@@ skipping 139 matching lines @@
 }
 
 remoting.init = function() {
   l10n.localize();
   var button = document.getElementById('toggle-scaling');
   button.title = chrome.i18n.getMessage(/*i18n-content*/'TOOLTIP_SCALING');
   // Create global objects.
   remoting.oauth2 = new remoting.OAuth2();
   remoting.debug =
       new remoting.DebugLog(document.getElementById('debug-messages'));
+  /** @type {XMLHttpRequest} */
+  remoting.supportHostsXhr = null;
 
   refreshEmail_();
   var email = getEmail();
   if (email) {
     document.getElementById('current-email').innerText = email;
   }
 
   remoting.setMode(getAppStartupMode());
   if (isHostModeSupported()) {
     var unsupported = document.getElementById('client-footer-text-cros');
@@ skipping 201 matching lines @@
     plugin.parentNode.removeChild(plugin);
   } else if (state == plugin.ERROR) {
     remoting.debug.log('Host plugin state: ERROR');
     showShareError_(/*i18n-content*/'ERROR_GENERIC');
   } else {
     remoting.debug.log('Unknown state -> ' + state);
   }
 }
 
 /**
-* This is the callback that the host plugin invokes to indicate that there
-* is additional debug log info to display.
-* @param {string} msg The message (which will not be localized) to be logged.
-*/
+ * This is the callback that the host plugin invokes to indicate that there
+ * is additional debug log info to display.
+ * @param {string} msg The message (which will not be localized) to be logged.
+ */
 function debugInfoCallback_(msg) {
   remoting.debug.log('plugin: ' + msg);
 }
 
 /**
-* Show a host-side error message.
-*
-* @param {string} errorTag The error message to be localized and displayed.
-* @return {void} Nothing.
-*/
+ * Show a host-side error message.
+ *
+ * @param {string} errorTag The error message to be localized and displayed.
+ * @return {void} Nothing.
+ */
 function showShareError_(errorTag) {
   var errorDiv = document.getElementById('host-plugin-error');
   l10n.localizeElementFromTag(errorDiv, errorTag);
   remoting.debug.log('Sharing error: ' + errorTag);
   remoting.setMode(remoting.AppMode.HOST_SHARE_FAILED);
 }
 
+/**
+ * Cancel an active or pending share operation.
+ *
+ * @return {void} Nothing.
+ */
 remoting.cancelShare = function() {
   remoting.debug.log('Canceling share...');
   remoting.lastShareWasCancelled = true;
   var plugin = /** @type {remoting.HostPlugin} */
       document.getElementById(remoting.HOST_PLUGIN_ID);
   try {
     plugin.disconnect();
   } catch (error) {
     remoting.debug.log('Error disconnecting: ' + error.description +
                        '. The host plugin probably crashed.');
     // TODO(jamiewalch): Clean this up. We should have a class representing
     // the host plugin, like we do for the client, which should handle crash
     // reporting and it should use a more detailed error message than the
     // default 'generic' one. See crbug.com/94624
     showShareError_(/*i18n-content*/'ERROR_GENERIC');
   }
   disableTimeoutCountdown_();
 }
 
+/**
+ * Cancel an incomplete connect operation.
+ *
+ * @return {void} Nothing.
+ */
+remoting.cancelConnect = function() {
+  if (remoting.supportHostsXhr) {
+    remoting.supportHostsXhr.abort();
+    remoting.supportHostsXhr = null;
+  }
+  if (remoting.session) {
+    remoting.session.removePlugin();
+    remoting.session = null;
+  }
+  remoting.setMode(remoting.AppMode.HOME);
+}
+
 function updateStatistics() {
   if (!remoting.session)
     return;
   if (remoting.session.state != remoting.ClientSession.State.CONNECTED)
     return;
   var stats = remoting.session.stats();
 
   var units = '';
   var videoBandwidth = stats['video_bandwidth'];
   if (videoBandwidth < 1024) {
@@ skipping 22 matching lines @@
   window.setTimeout(updateStatistics, 1000);
 }
 
 function showToolbarPreview_() {
   var toolbar = document.getElementById('session-toolbar');
   addClass(toolbar, 'toolbar-preview');
   window.setTimeout(removeClass, 3000, toolbar, 'toolbar-preview');
 }
 
 function onClientStateChange_(oldState) {
+  if (!remoting.session) {
+    // If the connection has been cancelled, then we no longer have a reference
+    // to the session object and should ignore any state changes.
+    return;
+  }
   var state = remoting.session.state;
   if (state == remoting.ClientSession.State.CREATED) {
     remoting.debug.log('Created plugin');
   } else if (state == remoting.ClientSession.State.BAD_PLUGIN_VERSION) {
     showConnectError_(remoting.ClientError.MISSING_PLUGIN);
   } else if (state == remoting.ClientSession.State.CONNECTING) {
     remoting.debug.log('Connecting as ' + remoting.username);
   } else if (state == remoting.ClientSession.State.INITIALIZING) {
     remoting.debug.log('Initializing connection');
   } else if (state == remoting.ClientSession.State.CONNECTED) {
-    remoting.setMode(remoting.AppMode.IN_SESSION);
-    recenterToolbar_();
-    showToolbarPreview_();
-    updateStatistics();
-    var accessCode = document.getElementById('access-code-entry');
-    accessCode.value = '';
+    if (remoting.session) {

[Wez, 2011/10/14 18:44:02]

We shouldn't even reach here if !remoting.session?

+      remoting.setMode(remoting.AppMode.IN_SESSION);
+      recenterToolbar_();
+      showToolbarPreview_();
+      updateStatistics();
+    }
   } else if (state == remoting.ClientSession.State.CLOSED) {
     if (oldState == remoting.ClientSession.State.CONNECTED) {
       remoting.session.removePlugin();
       remoting.session = null;
       remoting.debug.log('Connection closed by host');
       remoting.setMode(remoting.AppMode.CLIENT_SESSION_FINISHED);
     } else {
       // The transition from CONNECTING to CLOSED state may happen
       // only with older client plugins. Current version should go the
       // FAILED state when connection fails.
@@ skipping 19 matching lines @@
   } else {
     remoting.debug.log('Unexpected client plugin state: ' + state);
     // This should only happen if the web-app and client plugin get out of
     // sync, and even then the version check should allow compatibility.
     showConnectError_(remoting.ClientError.MISSING_PLUGIN);
   }
 }
 
 function startSession_() {
   remoting.debug.log('Starting session...');
+  var accessCode = document.getElementById('access-code-entry');
+  accessCode.value = '';  // The code has been validated and won't work again.

[Wez, 2011/10/14 18:44:02]

nit: Move this comment above the var accessCode line and re-phrase e.g. "Clear
the Access Code, since it cannot be used again."?

   remoting.username =
       /** @type {string} email must be non-NULL to get here */ getEmail();
   remoting.session =
       new remoting.ClientSession(remoting.hostJid, remoting.hostPublicKey,
                                  remoting.accessCode, remoting.username,
                                  onClientStateChange_);
   remoting.oauth2.callWithToken(function(token) {
     remoting.session.createPluginAndConnect(
         document.getElementById('session-mode'),
         token);
@@ skipping 12 matching lines @@
   var errorDiv = document.getElementById('connect-error-message');
   l10n.localizeElementFromTag(errorDiv, /** @type {string} */ (errorTag));
   remoting.accessCode = '';
   if (remoting.session) {
     remoting.session.disconnect();
     remoting.session = null;
   }
   remoting.setMode(remoting.AppMode.CLIENT_CONNECT_FAILED);
 }
 
+/**
+ * @param {XMLHttpRequest} xhr The XMLHttpRequest object.
+ * @return {void} Nothing.
+ */
 function parseServerResponse_(xhr) {
+  remoting.supportHostsXhr = null;

[Wez, 2011/10/14 18:44:02]

nit: Should we check that xhr == supportHostsXhr first?

   remoting.debug.log('parseServerResponse: status = ' + xhr.status);
   if (xhr.status == 200) {
     var host = JSON.parse(xhr.responseText);
     if (host.data && host.data.jabberId) {
       remoting.hostJid = host.data.jabberId;
       remoting.hostPublicKey = host.data.publicKey;
       var split = remoting.hostJid.split('/');
       document.getElementById('connected-to').innerText = split[0];
       startSession_();
       return;
@@ skipping 14 matching lines @@
   // Trim whitespace.
   // TODO(sergeyu): Do we need to do any other normalization here?
   return accessCode.replace(/\s/g, '');
 }
 
 function resolveSupportId(supportId) {
   var headers = {
     'Authorization': 'OAuth ' + remoting.oauth2.getAccessToken()
   };
 
-  remoting.xhr.get(
+  remoting.supportHostsXhr = remoting.xhr.get(
       'https://www.googleapis.com/chromoting/v1/support-hosts/' +
           encodeURIComponent(supportId),
       parseServerResponse_,
       '',
       headers);
 }
 
 remoting.tryConnect = function() {
+  document.getElementById('cancel-button').disabled = false;
   if (remoting.oauth2.needsNewAccessToken()) {
     remoting.oauth2.refreshAccessToken(function(xhr) {
       if (remoting.oauth2.needsNewAccessToken()) {
         // Failed to get access token
         remoting.debug.log('tryConnect: OAuth2 token fetch failed');
         showConnectError_(remoting.ClientError.OAUTH_FETCH_FAILED);
         return;
       }
       remoting.tryConnectWithAccessToken();
     });
@@ skipping 24 matching lines @@
     showConnectError_(remoting.ClientError.INVALID_ACCESS_CODE);
   } else {
     var supportId = remoting.accessCode.substring(0, kSupportIdLen);
     remoting.setMode(remoting.AppMode.CLIENT_CONNECTING);
     resolveSupportId(supportId);
   }
 }
 
 remoting.cancelPendingOperation = function() {
   document.getElementById('cancel-button').disabled = true;
-  if (remoting.getMajorMode() == remoting.AppMode.HOST) {
-    remoting.cancelShare();
+  switch (remoting.getMajorMode()) {
+    case remoting.AppMode.HOST:
+      remoting.cancelShare();
+      break;
+    case remoting.AppMode.CLIENT:
+      remoting.cancelConnect();
+      break;

[Wez, 2011/10/14 18:44:02]

nit: This might actually read better as an if...else.

   }
 }
 
 /**
  * Gets the major-mode that this application should start up in.
  *
  * @return {remoting.AppMode} The mode to start in.
  */
 function getAppStartupMode() {
   if (!remoting.oauth2.isAuthenticated()) {
@@ skipping 83 matching lines @@
   }
 }
 
 function recenterToolbar_() {
   var toolbar = document.getElementById('session-toolbar');
   var toolbarX = (window.innerWidth - toolbar.clientWidth) / 2;
   toolbar.style['left'] = toolbarX + 'px';
 }
 
 }());